可再加工的聚合物网络含有基于硫的透动态共价交叉链接和透或非透的静态交叉链接
Logan M Fenimore1, Mohammed A Bin Rusayyis2, Claire C Onsager3
1Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, 60208, USA.
Macromolecular rapid communications
|July 11, 2024
概括
这项研究引入了用静态交叉连接增强的共价适应网络 (CAN),保持可回收性. 这些网络表现出受交叉链内容和聚合物骨干动力学影响的可调节的应力放松行为.
科学领域:
- 聚合物化学 聚合物化学
- 材料科学 材料科学 材料科学
背景情况:
- 共价适应性网络 (CAN) 提供动态特性,但往往缺乏稳定性.
- 整合永久交叉连接可以提高网络稳定性,而不会损害可回收性.
研究的目的:
- 为了合成和表征基于多-基甲酸盐 (PHMA) 和多-基甲酸盐 (PLMA) 的CAN,具有静态和动态交叉链接.
- 调查静态交叉链内容对这些CAN的机械性能的影响,特别是应力松.
- 阐明网络架构,聚合物流动性和压力放松机制之间的关系.
主要方法:
- 合成PHMA和PLMA网络,使用 bis(2-甲烯) 氧乙烯二硫化物 (DSDMA) 作为静态交叉连接器和BiTEMPS甲酸盐作为动态交叉连接器.
- 评估网络的稳定性和可回收性,包括交叉链密度恢复.
- 在不同静态交叉链度下分析压力放松反应.
- 确定激活能量来缓解压力,以了解潜在的机制.
主要成果:
- 成功合成了具有可调节静态交叉连接内容的强大且可回收的CAN.
- 经过回收利用后,已经证明了交叉链密度的完全恢复,证实了网络完整性.
- 在离散性CAN中观察到明显的压力放松行为,而不是那些透的静态交叉链接.
- 确定BiTEMPS甲酸盐解离在非透网络中主导放松,而侧链细分放松 (β放松) 则支配透网络中的放松.
结论:
- 开发的CANs提供了一种有前途的方法,用于创建具有增强机械性质和可回收性质的材料.
- 静态交叉链和动态共价键之间的相互作用允许精确控制材料反应.
- 了解主要的放松机制 (交叉链解离与细分运动) 对于设计先进的可适应材料至关重要.
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